netdev - Re: [PATCH net-next v6 08/12] net: homa: create homa

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <a3295c97-9734-4baa-b9c7-408c54b0702c@lunn.ch>
Date: Tue, 4 Feb 2025 20:41:48 +0100
From: Andrew Lunn <andrew@...n.ch>
To: John Ousterhout <ouster@...stanford.edu>
Cc: Paolo Abeni <pabeni@...hat.com>, Netdev <netdev@...r.kernel.org>,
	Eric Dumazet <edumazet@...gle.com>, Simon Horman <horms@...nel.org>,
	Jakub Kicinski <kuba@...nel.org>
Subject: Re: [PATCH net-next v6 08/12] net: homa: create homa_incoming.c

> > If unprivileged applications could use unlimited amount of kernel
> > memory, they could hurt the whole system stability, possibly causing
> > functional issue of core kernel due to ENOMEM.
> >
> > The we always try to bound/put limits on amount of kernel memory
> > user-space application can use.
> 
> Homa's receive buffer space is *not kernel memory*; it's just a large
> mmapped region created by the application., no different from an
> application allocating a large region of memory for its internal
> computation.

ulimit -v should be able to limit this, if user space is doing the
mmap(). It should be easy to test. Set a low enough limit the mmap()
should fail, and i guess you get MAP_FAILED and errno = ENOMEM?

	Andrew